cpufreq: Preserve policy's boost state after resume

If the global boost flag was enabled and policy boost flag was disabled
before a suspend resume cycle, cpufreq_online() will enable the policy
boost flag on resume.

While it is important for the policy boost flag to mirror the global
boost flag when a policy is first created, it should be avoided when the
policy is reinitialized (for example after a suspend resume cycle).

Though, if the global boost flag is disabled at this point of time, we
want to make sure policy boost flag is disabled too.

Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/de5c72a0af101049204305c73cd30eb3a3e7b4a0.1745511526.git.viresh.kumar@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: vireshk

drivers/cpufreq/cpufreq.c

@@ -1623,8 +1623,13 @@ static int cpufreq_online(unsigned int cpu)
 	if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver))
 		policy->cdev = of_cpufreq_cooling_register(policy);
 
-	/* Let the per-policy boost flag mirror the cpufreq_driver boost during init */
-	if (cpufreq_driver->set_boost && policy->boost_supported) {
+	/*
+	 * Let the per-policy boost flag mirror the cpufreq_driver boost during
+	 * initialization for a new policy. For an existing policy, maintain the
+	 * previous boost value unless global boost is disabled.
+	 */
+	if (cpufreq_driver->set_boost && policy->boost_supported &&
+	    (new_policy || !cpufreq_boost_enabled())) {
 		ret = policy_set_boost(policy, cpufreq_boost_enabled());
 		if (ret) {
 			/* If the set_boost fails, the online operation is not affected */